Mold for slide fasteners



April13,1948- J..N.KUZMICK 2,439,433

MOLD FOR SLIDE FASTENERS Filed May 5, 1944 4 Sheets-Sheet 1 INVENTOR. sph #761 577: ink

' A ril 13, 1948.

J. N, KUZMICK MOLD FOR SL'IDE FASTENERS Filed May 3, 1944 4 she ts-sheet 2 Jfforng/E;

J. N. KUZMICK MOLD FOR SLIDE FASTENERS April 13, 1948.

Filed May s, 1944 4 Sheets-Sheet :s

April 13, 1948. J. N. KUZMICK MOLD FOR SLIDE FASTENERS 4 Sheets-Sheet 4Filed May 5, 1944 Patented Apr. 13, 1948 MOLD FOR SLIDE FASTENERS JosephN. Kuzmick, Clifton, N. J., assignor to Conmar Products Corporation,Newark, N. J., a corporation of New Jersey Application May 3, 1944,Serial No. 533,989

11 Claims.

This invention relates to the manufacture of slide fasteners and moreparticularly to the molding of conventionally shaped slide fastenerelements directly onto a tape.

In the conventionally shaped slide fastener element or scoop, thecoupling portion or head of the element has for its coupling orinterlocking means a projection on its top face and a depression orpocket on its bottom face. Such an element or scoop may be moldeddirectly onto the edge of a tape in a two-part mold between which thetape is received at the meeting or parting plane of the mold, but a coremeans must be used to form the depression or pocket in the element head.

Such a mold usually comprises two mold sections separable in the planeof the tape, each mold section having a mold cavity corresponding toone-half of the element or scoop as divided by a vertical medial planeof the element. When the mold sections close with the tape edge betweenthem, these mold cavities mate to define a single mold cavity in theshape of the slide fastener element or scoop except for the pocket ordepression. The tape onto which the element or scoop is molded isfedbetween the mold sections and extends into the thus formed cavity inan amount such that the mounting portion .or laws of the element orscoop is molded onto the tape edge or about the bead of the tape. Tocomplete the mold structure, core means suitably arranged andcooperating with the mold sections must also be provided for forming theelement pocket; and runners and sprue channels for the flow of themoldable material to the cavity must also be provided in the mold.

Considerable difficulties, however, are encountered in producing aworkable arrangement in which the core means and the runners and spruechannels are positioned and operate with out mutual interference.Attempts to solve the involved difficulties have led to processes inwhich only one scoop at a time is molded onto the tape; but suchprocesses are time consuming and uneconomical. It has also beensuggested to use elements or scoops which can be molded onto the tapewithout the use of cores, but such elements or scoops are of anon-conventional type since the coupling depression must be made so asto be open to a side of the element.

The prime object of my present invention centers about the provision ofa mold apparatus for molding conventionally shaped slide fastenerelements directly onto the edge of a tape in which a plurality or agroup of slide fastener elements or scoops may be molded onto the tapeat one time without incurring the difficulties heretofore encounteredarising from the interference in positioning and operation between thecore members and the runners and sprue channels.

To the accomplishment of this object and such other objects as mayhereinafter appear, the present invention relates to the mold as soughtto be defined in the appended claims and described in the followingspecification taken together with the accompanying which:

Fig. i is a perspective View of a fragment of a slide fastener stringershowing a group of elements or scoops such as are molded at one timeonto the tape in the method and mold of the present invention;

Fig. 2 is an elevational and fragmentary view of a section such as themovable section of a twopart mold of the present invention, this viewbeing taken from in front of the parting or meeting plane of the moldsection and showing in section core means used according to thisinvention, the view being taken in cross-section in the plane and in thedirection of the line 2--2 of Fig. 4;

Fig. 2A is a similar view of the other, such as the fixed, mold sectionof the mold and taken in cross-section in the plane and in the directionof the line 2A, 2A of Fig. 4;

Fig. 3 is a view similar to Fig. 2 illustrating a modified mold and coreconstruction;

Fig. 4 is a partially sectioned elevation of the two-part mold showingthe two mold sections and the cores in molding position;

Fig. 5 is a similar view of the mold shown in Fig. 4 and showing themold sections at a stage during their opening operation;

Fig. 6 is a view similar to Fig. 5 showing the mold sections at afurther advanced stage of their opening operation and showing the coresseparated from the movable mold section;

Fig. '7 is a perspective view of the tape and the parts molded thereonin a single operation and showing the same still supported on the coremeans, corresponding to the stage of operation shown in Fig. 6; and

Fig. 8 is a front elevational view of Fig. 7 and is explanatory of thestep of stripping the molded stringer from the supporting core means.

The method of the present invention and the molding apparatus thereofwill now be explained first by reference to the product finally obtainedand then by reference to the structure of the mold.

Referring first to Fig. 1 of the drawings, the slide fastener stringerproduced comprises slide fastener elements or scoops E molded in spacedrelation at the edge and around the bead B of a suitable tape T. Each ofthe elements or scoops E is conventionally shaped and comprises acoupling portion or head C and a mounting portion M. The couplingportion or head C of each eledrawings, in

3 ment has for interlocking or coupling purposes the projection P on oneface and the depression D on its opposite face; The mounting portion Mconsists of the two jaws J, J. The stringer portion shown in Fig. 1 maybe taken to repre sent the product obtained in a single operating stepof the method of the present .invention,,.

namely, a plurality or group of elements or scoops E molded at one timeonto the tape.

It will be understood that the productlof'Figs 1 is obtained after theappending sprues have been removed from the product as molded, and thatthe stringer of Fig. 1 is only representative l Q's-l 2 for defining thepocket of the element, and is so positioned, mounted and: operated thatit is compatible with'the arrangement: and operation of the runners andsprue channels,,the construction being, moreover, such that a pluralityor group of core members may be employed so that .a,plural ity or groupof slide fastener'elements or" scoops maybe molded in a single operatingstep: of the method;

This; object-;is attained by mounting the core memb.ers;28,:28-on"one ofthe mold sections and" since a smaller or a larger number of elementsmay comprise the group .of elements or scoops which 'is simultaneouslyproduced in a molding step.

Referring now to Figs. 2 and 2A, the mold of thepresent invention isshown to comprise a two-part mold having a movable section or ejectordieM and a fixed section or cover die M which 1 are adapted to mate asshown in Fig. 4 of the lementor scoop as-divided by a vertical medialpiane of the element. Therefore, when the mold sections M. and "M closewiththe edge of the tape 'between them, each of the mold cavities H3mates with its counterpart mold cavity ii! to define a single moldcavity in the shape of the slide" fastener element or scoop except forthe pocket-or depression D which is to be formed in the element. Themold M is also prov ded with interconnecting channel cavities it, 14 andthe mold cavityM is correspondingly provided with the interconnectingchannel cavities l6, 6 for the purpose of receiving the bead B of thetape T.

The mold sections M and M are formed with suitablerunners and spruechannels for the flow ofthe moldable material, an injection moldingmethod being preferably used with the mold of the present invention. Tothis end the fixed mold section M is formed with a main charging duct I8themouth of which communicates with a suitable injection nozzle (notshown) and the movable mold section M is formed with a depression 2i!registering with the main duct l8. The depression 25! opens in theopposite direction'sto-runners 22 and 24 formed in the mold section Mand sprue channels 26, 26 are also formed in this movable mold sectionconnecting forintercommunication the runners with the cavities it, Hi,and hence with'the formed cavitiesof the mold. Thus it will be'notedthatitis preferred to form therunners and the; sprue channel's-inonly oneof the two'mold sections, these'thus having a-serni-circularcross-section;

For defining and forming the depressions or pockets D of the elements,I' provide core means comprising the plurality of core members 28, 28.Each core member has a corepart for forming the" pocket and a supportingstem or core bar 32.

To carry out the object of the present invention, each core member 23 isso constructed; mounted and-operated that the core part 3% thereofispositionable in the formed mold cavity preferably on the movable moldsection M", and mounting the same on said mold section so that the moremembers are movable thereon transversely of the meeting plane of suchmold sec-' tien. Stillreferringto Fig. 2 of the drawing, each stem 32of. the. core members is mounted on andcarried by themold section M" andis movable transversely of the meeting or parting plane of this moldsection, each core member beingthu's:

mountedjfor reciprocable movement in the mold.

section in a, throughchannel 34 formed in they moldsection. The fixedmold ,section M is in turn provided .with. registering. depressions or,cavities 3t, St'iorreceiving the cavity intruding? ends of the coremembers 28, 28; It will be noted? that considering two. adjacent, orconsecutive moldcavities iii-i2, l0,!2, a core-part 3i) is positionedbetween two successive cavities and it ,will also be noted that thecavity intruding part of its core member is positioned betweentwosuccessive'sprue openings. By reason of this arrange ment of the coremembers, all interference betweenthe positioning and operation thereofand .the positioning and use of the runners and sprue channels is notonly eliminated, but a plurality or group of slide fastener elements maybe molded in one operating step of the method.

This provided for construction and arrange-- .ment also possesses otheradvantages. Thus, as will'be evident from a consideration of Fig. 2, thestems 28, 28' of the core members, mounted in-- clinedly in themoldsection M, have their upper? faces 38 contiguous to the correspondinglyinclined part of the sprue channels 26 so that the" formed or moldedchannel stem and-connecting sprues are supported-by the stems of thecore memberswhen the mold sections are'separated.

This constructionmay be also modified as shown- :in Fig. 3of thedrawings so that the bottom faces at, dilof'the modified core stems 28,28 shown in this figure are'just contiguous to the edge 42, tZrof themold cavity it, it" whereby the cores not only'help define the moldcavities but serve to further support at their faces ll}, 40 the tapewith its molded elements and appending channelfstem, and sprues. Otherparts in themodification of Fig. 3:are similar to those of Fig. 2 endsare designated by corresponding but primed reference characters.

In Figs. 4 to 8 aredepicted sequential steps in the method of thepresent invention. Fig. 4 depicts thecondition of operation with themold sections M and. M closed just after a molding operation. Fig. 5,depicts an immediately sub-. sequent stage of the operation, the movablemold M and its associated parts being shown separating, from the fixedmold M Fig. 6 depicts the next immediate stage of operation wherein theT and the parts which have been molded th reto are separated from themovable mold section M and are supported solely by the core members 28,23. I Fig. 7 depicts the parts minus the mold sections when the tape andthe parts molded thereto have been completely separated members 28 it,When the mold sectionsMi and M ;are closed; (Fig..4):,-the coremembersZS, 28 assume the posi: tion shown inFis; 4 with theincore parts3il, 3flI allproperly positioned inathe formed cavities W -i2; of themoldq Almoldable materialistheninjectedintotheimold through the maincharg e, ing channel i3 and the same, flows through the" runners and sprue channelsinto themold cavities Fig fi of the drawingswhich; at a.predetermined point of the. movement ofthe mold: section. M'v,-, is

stopped while the; mO 1d SCtiOn ispermitted to continue .its movement inthe direction indicated by the arrow-iB in Big. 7., Thus1aj'knockout or:ej ecting movement of. the core members ,2-8, I25 is produced,, thecore-parts 39, i 39 thereof being, thus freed fromboth of thelrnoldsections M21 and; Mfl as clearly depicted in liigt 6 of the drawings, inwhich position the tape and; ,the molded parts are supported solely bythe termini or core 'parts ofthe. core membersas bestshown in; Fig 'l;of the drawings. In practice the; mold section ,Mf with 5 its carriedparts is moved prior tothe knockout 1 operation a reater distance than:is indicatediin Fig. -6 of the 1 drawings, so that the sprue; 44s is eeto. 1 a tl fi e1 m ds on wi be understood thatthe construction depictedin Fist i a o e em ar 0 a modifi o r t n: wherein thernold section- M':together iwith its carried parts are all moved in thedirectionpindicated by the arrow 58 ,to a stop position, whereupon theak nockoutorejecting operation is: pro: 4 ducecl moving the rackfi andyitsassociatedcore members 2'3 irrthe oppositeg direction and F g-H i e r wninto the position indicated i ings 7 1 1 t e kn mut p s t on J ta a I rr l 55. mold sections, at the termini of the core mem-v r 3, 23 as b t}h w n F 1?- {It i d w za e .atut i t met op a ion rtoq rm is t th t arlw o ded a ts in; r i io i ndthis i is obtained b th disp s ti n asw ltha M n ha e m e r-e ve to the: core; members as explained above; inQQOnnectiOn; 5 withgboth-Fig. 2;and Fig.3 ofthe-drawings; ;With a firmsupportsuitable means may beused at this stage to cut off from theelements E the gatea;

molded parts are; solely supported free I of both runner and sprueappendagesd-tofiii: aI-Iowever,

28,-,the tape 1- andiits molded parts may then be latter inthe-directionindicatedyby the arrowszfiil in :ofwthe drawings; rIn {this:movement tha i tape and; the moldedelements rqare freed from; the; 75

core" supports, whereupomaz new sectionrof the;

taperisfed imposition and the mold sections are closed? for molding asuccessive it groups of slider fastener elements; l

The 'practicexof thecmethodxof the p resentinvention: and the"construction and operation of the moldsthereof will in the main vbefully :apparent from the above detaileddescription -By means of thismethod and molding apparatus: a? plurality L01 a group of a slide.fastener elements or scoops "of conventional shape may be molded iontothe tape atone time.=-This may be accomplished by. means *of a moldsand core mem bers, the core members being desirably mounted and;supported in 'one of tthe imold sections.- The 5 construction andoperation T are. furtherl. more; such that-a grouprofelements may besimultaneously molded: employing a group? oil core members which,nevertheless, may be so disposed asinot only notto interfe'redwith theinjection runners and spruef channels, but which may: i be i I employedto) assist in I supporting the molded runner stems 1 and sprues andsthus 1 aid-in handling and feeding the molded product aftereach moldingoperation;

It willu be understood: :that according to" the present invention eanymolding material maybe 1 used which can be reduced to aplastic state byheat, such as thermoplastic and thermosetting materials and metals" andalloys suitable 1 for die 1 casting. It will. also' beunderstood thatchangesmay be madeiinthe meth'od and in the" apparatus described withoutdeparting. from! the spirit.v of the invention definedi in the followingclaims;

the 'edge of the tape, core: members positionable said :cavities vfor;defining the: pockets? of the elements, "each core being? mounted :ontheilongi tudin'alaiedgeiof a fiat core bar -near one end or the saidlbars passing slidably through i one of said mold sectionsxior movementin thedirec-av tion of movement "of 'the mold sections.

l 2; Arnold :for directly molding at one time onto i the edgeaof z aatape a pluralityv of slide fastener-1 elements) having t headsv withsloping front swalls and pockets formed. in the heads for interlockeding purposes, said mold t comprising two" mold: sections relatively,reciprocableatoward and away from brie-another andadapted: to receivethetape; therebetweenythe parting plane of the moldv secstionslcorrespondin to the plane of the :tape said; mold sections havingmold cavitieswhich define a 1; p u ality of s d st ner elem ts s ace aone: e Wee-ofthet i co emembe s p s t nable n said: cavit s 1 r defin nth p ts the elements, eachcore; being mounted; on the longil t al-edeeioa flat r b nn a r endo 1 the abar saidgbars passing slidablythroughlone, of ai :mold s n or m-ove ntii "th d ew tion of movement ot the moldsections said bars; whenyvi w ec ion b n tilt d, t'an n lthewfrontapproximately. the same as the :slope of Wa11 i th ,u81 m nt hed-l" a ,l -tA ,.-m ld $01" :d re flvame An e 7 onto the edge of a tape aplurality of slide fastener elements having heads with sloping frontwalls and pockets formed in the heads for interlocking purposes, saidmold comprising two mold sections relatively reciprocable toward andaway from one another and adapted to receive the tape therebetween, theparting plane of the mold sections corresponding to the plane of thetape, said mold sections having mold cavities which define a pluralityof slide fastener elements spaced along the edge of the tape, coremembers positionable in said cavities for defining the pockets of theelements, each core being mounted on the longitudinal edge of a fiatcore bar near one end of the bar, said bars passing slidably through oneof said mold sections for movement in the direction of movement of themold sections, said mold having asprue and gates leading to the moldcavities, said gates extending across the aforesaid bars and leading tothe bottom edge of the front wall of the element head.

a. A mold for directly molding at one time onto the edge of a tape aplurality of slide fastener elements having heads with sloping frontwalls and pockets fox-med in the heads for interlocking purposes, saidmold comprising two mold sections relatively reciprocable toward andaway from one another and adapted to receive the tape therebetween, theparting plane of the mold sect'ions corresponding to the plane of thetape, said mold sections having mold cavities which define a pluralityof slide fastener elements spaced along the edge of the tape, coremembers positionable in said cavities for defining the pockets of theelements, each core being mounted on the longitudinal edge of a fiatcore bar near one end of the bar, said bars passing slidably through oneof said mold sections for movement in the direction of movement of themold sections, said bars when viewed in section being tilted at an angleapproximately the same as the slope of the front wall of the elementhead, said mold having a sprue and gates leading to the mold cavities,said gates extending across the aforesaid bars and leading to the bottomedge of the front wall of the element head.

5. A mold for molding a plurality of slide fastener elements directly onthe edge of a tape, each of said elements having a pocketed head with asloping front wall, said mold comprising a cover die and an ejector diereciprocable toward and away from the cover die with the tapetherebetween, said die portions having cavities defining a plurality ofslide fastener elements spaced along the edge of the tape, a pluralityof cores for defining the pockets in the heads, each core being' carriedon the longitudinal edge of a flat core bar near one end of the corebar, said core bars being slidably received in the ejector die formovement in the direction of movement of said'die, and means connectingsaid core bars for movement in unison, whereby on opening of the die thecores may be moved to a position intermediate the cover and ejectordies, thereby separating the elements from the ejector die.

6. A mold for molding a plurality of slide fastener elements directly onthe edge of a tape, each of said elements having a pocketed head with asloping front wall, said mold comprising a cover die and an ejector diereciprocable toward and away from the cover die with the tapetherebetween, said die portions having cavities defining a plurality ofslide fastener elements spaced along the edge of the tape, a pluralityof cores for defining the pockets in the heads, each core being carriedon the longitudinal edge of a fiat core bar hear one end of the timebar, said core bars being slidably received in the ejector die formovement in the direction of movement of said die, said core bars whenviewed in section being tilted at an angle approximately the same as theangle of the front wall of the element head, and means connecting saidcore bars for movement in unison, whereby on opening of the die thecores may be moved to a position intermediate the cover and ejectordies, thereby separating the elements from the ejector die.

7. A mold for molding a plurality of slide fastener elements directly onthe edge of a tape, each of said elements having a pocketed head with asloping front wall, said mold comprising a cover die and an ejector diereciprocable toward and away from the cover die with the tape'therebetween, said die portions having cavities defining a plurality ofslide fastener elements spaced along the edge of the tape, a pluralityof cores for defining the pockets in the heads, each core being carriedon the longitudinal edge of a fiat core bar near one end of the corebar, said core bars being slidably received in the ejector die for.movement in the direction ofmovement of said die, said cover die havinga spruehole leading to gate passages at the parting plane, said gatepassages terminating in gates extending transversely of the core barsand leading into the bottom edges of the front walls of the elementheads, and means connecting said core bars for movement in unison,whereby on opening of the die the cores may be moved to a positionintermediate the cover and ejector dies, thereby separating the elementsfrom the ejector die.

8. A mold for molding a plurality of slide fastener elements directly onthe edge of a tape, each of said elements havinga pocketedhead with asloping front wall, said mold comprising a cover die and an ejector diereciprocable toward and away from the cover die with the tapetherebetween, said die portions having cavities defining a plurality ofslide fastener elements spaced along the edge of the tape, a pluralityof cores for defining the pockets in the heads, each core being carriedon the longitudinal edge of a flat core bar near one end of the corebar, said core bars being slidably received in the ejector die formovement in the direction of movement of said die, said core bars whenviewed in section being tilted at an angle approximately the same as theangle of the front wall of the element head, said cover die having asprue-hole leading to gate passages at the parting plane, said gatepassages terminating in gates extending upwardly along and transverselyof the core bars and leading into the bottom edges of the front walls ofthe element heads, and means connecting said core bars for movement inunison, whereby on opening of the die the cores may be moved to a position intermediate the cover and ejector dies, thereby separating theelements from the ejector die. i

9. A mold as defined in claim 1, in which the mold includes sprue,runner, and gate passages leading to the mold cavities, and in which thebars and gate passages are so relatively located as not to intersect,whereby the tape, elements, gates, runner, and sprue may be strippedfrom the cores after the mold is opened.

1 0 A mold as defined in claim 1, in which the mold includes sprue,runner and gate passages leading to the mold cavities, and in which the9 bars are disposed parallel to one another, and in which the gatepassages are disposed parallel to one another and transversely of thelongitudinal axis of the bars.

11. A mold as defined in claim 1, in which the mold includes sprue,runner and gate passages leading to the mold cavities, and in which thebars are disposed parallel to one another, and in which the gatepassages are disposed parallel to one another and transversely of thelongitudinal axis of the bars, and in which the gate passages REFERENCESCITED The following references are of record in the file of this patent:

Number UNITED STATES PATENTS Name Date Corner Mar.,23, 1937 De MattiaApr. 23, 1940 Dahlin May 12, 1942 Poux Sept. 29, 1942 Poux Nov. 24, 1942Marsh Sept. 28, 1943 Popp July 10, 1944 FOREIGN PATENTS Country DateNumber Great Britain Nov. 19, 1931

